Prevent dynamically multiplied tuple constants from being deduplicated. Only...

Prevent dynamically multiplied tuple constants from being deduplicated. Only the constant part is considered for them.

Cython/Compiler/ExprNodes.py

@@ -199,10 +199,11 @@ def make_dedup_key(outer_type, item_nodes):
     """
     item_keys = [
         (py_object_type, None) if node is None
-        else make_dedup_key(node.type, node.args) if node.is_sequence_constructor
+        # For sequences and their "mult_factor", see TupleNode.
+        else make_dedup_key(node.type, [node.mult_factor if node.is_literal else None] + node.args) if node.is_sequence_constructor
         else make_dedup_key(node.type, (node.start, node.stop, node.step)) if node.is_slice
         else (node.type, node.constant_result) if node.has_constant_result()
-        else None
+        else None  # something we cannot handle => short-circuit below
         for node in item_nodes
     ]
     if None in item_keys:
@@ -7989,7 +7990,9 @@ class TupleNode(SequenceNode):
             return
 
         if self.is_literal or self.is_partly_literal:
-            dedup_key = make_dedup_key(self.type, self.args) if self.is_literal else None
+            # The "mult_factor" is part of the deduplication if it is also constant, i.e. when
+            # we deduplicate the multiplied result.  Otherwise, only deduplicate the constant part.
+            dedup_key = make_dedup_key(self.type, [self.mult_factor if self.is_literal else None] + self.args)
             tuple_target = code.get_py_const(py_object_type, 'tuple', cleanup_level=2, dedup_key=dedup_key)
             const_code = code.get_cached_constants_writer(tuple_target)
             if const_code is not None:

tests/run/for_in_iter.py

@@ -61,6 +61,37 @@ def for_in_literal_mult_list():
         l.append(i)
     return l
 
+
+def listcomp_over_multiplied_constant_tuple():
+    """
+    >>> listcomp_over_multiplied_constant_tuple()
+    [[], [1, 2, 3], [1, 2, 3, 1, 2, 3], [1, 2, 3, 1, 2, 3, 1, 2, 3], [1, 2, 3, 1, 2, 3]]
+    """
+    return [
+        [i for i in (1, 2, 3) * 0],
+        [i for i in (1, 2, 3) * 1],
+        [i for i in (1, 2, 3) * 2],
+        [i for i in (1, 2, 3) * 3],
+        [i for i in (1, 2, 3) * 2],
+    ]
+
+
+@cython.test_assert_path_exists('//ReturnStatNode//ForInStatNode//TupleNode')
+@cython.test_fail_if_path_exists('//ReturnStatNode//ForInStatNode//ListNode')
+def listcomp_over_multiplied_constant_list():
+    """
+    >>> listcomp_over_multiplied_constant_list()
+    [[], [1, 2, 3], [1, 2, 3, 1, 2, 3], [1, 2, 3, 1, 2, 3, 1, 2, 3], [1, 2, 3, 1, 2, 3]]
+    """
+    return [
+        [i for i in [1, 2, 3] * 0],
+        [i for i in [1, 2, 3] * 1],
+        [i for i in [1, 2, 3] * 2],
+        [i for i in [1, 2, 3] * 3],
+        [i for i in [1, 2, 3] * 2],
+    ]
+
+
 class Iterable(object):
     """
     >>> for_in_pyiter(Iterable(5))

tests/run/tuple_constants.pyx

@@ -46,9 +46,9 @@ def return_folded_tuple():
 def return_nested_tuple():
     """
     >>> return_nested_tuple()
-    (1, (2, 3), (3, (4, 5)))
+    (1, (2, 3), (3, (4, 5), (2, 3, 2, 3)))
     """
-    return (1, (2, 3), (3, (4, 5)))
+    return (1, (2, 3), (3, (4, 5), (2, 3) * 2))
 
 @cython.test_assert_path_exists("//TupleNode",
                                 "//TupleNode[@is_literal = true]")
@@ -71,6 +71,32 @@ def return_constant_tuple2():
     """
     return (1,2)
 
+
+def return_multiplied_constant_tuple(n):
+    """
+    >>> tuples = return_multiplied_constant_tuple(2)
+    >>> type(tuples) is tuple
+    True
+    >>> for t in tuples: print(t)
+    ()
+    (1, 2, 3)
+    (1, 2, 3, 1, 2, 3)
+    (1, 2, 3, 1, 2, 3, 1, 2, 3)
+    (1, 2, 3, 1, 2, 3)
+    (1, 2, 3, 1, 2, 3)
+    ((1, 2, 3, 1, 2, 3), (1, 2, 3), (1, 2, 3, 1, 2, 3))
+    """
+    return (
+        (1, 2, 3) * 0,
+        (1, 2, 3) * 1,
+        (1, 2, 3) * 2,
+        (1, 2, 3) * 3,
+        (1, 2, 3) * 2,
+        (1, 2, 3) * n,
+        ((1, 2, 3) * n, (1, 2, 3), (1, 2, 3) * n),
+    )
+
+
 @cython.test_assert_path_exists("//TupleNode",
                                 "//TupleNode[@is_literal = true]")
 @cython.test_fail_if_path_exists("//TupleNode[@is_literal = false]")